Method and apparatus for turning workpieces and utilizing programmed data

ABSTRACT

Disclosed here are methods and automatic apparatus for grinding cylindrical workpieces, such as the contoured rolls used in metal rolling mills. The methods and apparatus involve (1) automatic finding of the lengthwise center of rolls of different and undetermined lengths so as to establish a reference position for the execution of a numerically programmed path defined relative to the center of a roll as a point of symmetry, (2) the storage of the successive instructions of multi-axis movements making up a numerically defined profile or contoured path, and the use of those instructions repeatedly and in whole or in part as called for by different ones of a sequence of commands read from storage and executed in succession, (3) the automatic alignment of the roll axis parallel to the longitudinal axis of motion in a grinding machine by pivoting of one end of the roll about the other until the sensed difference in positions of the roll surface, along an axis transverse to the longitudinal axis and at locations near opposite ends of the roll, is changed to a predetermined fraction of the originally sensed difference, (4) the initiation of grinding passes from that end of a roll which is largest in diameter, so as to avoid &#39;&#39;&#39;&#39;digging in&#39;&#39;&#39;&#39; or increasing the depth of wheel bite as the wheel moves lengthwise of the roll, (5) the execution of continuous passes of the grinding wheel with pre-programmed values of feed rate, wheel speed, roll speed, continuous infeed and incremental infeed until a pre-programmed thickness of material has been removed from the roll surface, and (6) the grinding down of a roll until it is reduced to a diameter equal that of a previously ground roll of a matched pair. These functions are all obtained by the calling out and execution of pre-established routines in response to the reading from storage of pre-programmed sequence commands, so that in the disclosed method and apparatus there is an automatic progression from each type of operation to the next, and with the following of numerically defined profile whenever it is required.

United States Patent Clark, Jr.

|54| METHOD AND APPARATUS FOR TURNING WORKPIECES AND UTILIZING PROGRAMMED DATA [72] Inventor: Stephen C. Clark, Jr., Phoenixville, Pa.

[73] Assignee: The lngersoll Milling Machine Company,

Rockford, Ill.

[22] Filed: Jan. 25, 1971 i [21] Appl. No.: 109,522

Related US. Application Data [62] Division of Ser. No. 790,323, Jan. 10, 1969.

[52] U.S.Cl. ..5l/165 TP,51/49, 51/289 R,

318/569 [51] Int. Cl ..B24b 5/04 [58] Field ofSearch ..5l/49, 165 R, 165 TP, 165.71,

5l/l65.74, 165.75, 165.76, 165.77, 289 R, 326, 327; 82/14 B, 14 D, 21 B; 318/569, 570, 571

Primary Examiner-Lester M. Swingle Attorney-Wolfe, Hubbard, Leydig, Voit & Osann, Ltd.

[451 Apr. 4, 1972 [57] ABSTRACT Disclosed here are methods and automatic apparatus for grinding cylindrical workpieces, such as the contoured rolls used in metal rolling mills. The methods and apparatus involve (l) automatic finding of the lengthwise center of rolls of different and undetermined lengths so as to establish a reference position for the execution of a numerically programmed path defined relative to the center of a roll as a point of symmetry, (2) the storage of the successive instructions of ulti-axis movements making up a numerically defined profile or contoured path, and the use of those instructions repeatedly and in whole or in part as called for by different ones of a sequence of commands read from storage and executed in succession, (3) the automatic alignment of the roll axis parallel to the iongitudinal axis of motion in a grinding machine by pivoting of one end of the roll about the other until the sensed difference in positions of the roll surface, along an axis transverse to the longitudinal axis and at locations near opposite ends of the roll, is changed to a predetermined fraction of the originally sensed difference, (4) the initiation of grinding passes from that end of a roll which is largest in diameter, so as to avoid digging in or increasing the depth of wheel bite as the wheel moves lengthwise of the roll, (5) the execution of continuous passes of the grinding wheel with pre-programmed values of feed rate, wheel speed, roll speed, continuous infeed and incremental infeed until a pre-programmed thickness of material has been removed from the roll surface, and (6) the grinding down of a roll until it is reduced to a diameter equal that of a previously ground roll of a matched pair. These functions are all obtained by the calling out and execution of preestablished routines in response to the reading from storage of pre-programmed sequence commands, so that in the disclosed method and apparatus there is an automatic progression from each type of operation to the next, and with the following of numerically defined profile whenever it is required.

11 Claims, 27 Drawing Figures 7 PATENTED R 4W2 3,653,161 SHEET 030! 18 Stephen C. C/arahJn 4/444 VHLF/ PATENTEDAPR 4 I972 SHEET GMUF 18 lwN N ix x VIZ/\DTC) Stephen C. C fi/M6441, My.

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SHEET 080? 18 H SIGNAL Ufr m H m 05 1M, K 33.0000 PIC-L68 C1040 WM 159 5% WT GATES @1 PRESET GATES was jl 1% @{DRESET GATES] 9 IIBQ- E V C I DIRE I 331 u BIDIRECTIONAL SENSOR AM IL PULSER IN DOWN COUNTER '70 m ZERO W o FIG (5F 9 252 O READOUT GATES] si GrQAL @+'p s @M] 29130 15 it L190 ,IN FIGIO I85 JU OUT DIRECTION uP bm ggcno L, SENSER M IL g, p s R- 'IN OWN COUNTEK READOUT GQTES] QJ'REKTE/QTO 9 6fepher1 Clc/qr/f dn @MrQAA/M VJ? M @TTOR/QLY/ METHOD AND APPARATUS F OR TURNING BACKGROUND OF THE INVENTION WORKPIECES AND UTILIZING PROGRAMME!) DATA The present invention relates in general to methods and apparatus for the machining of workpieces, and while it will find TAB LE OF CONTENTS advantageous use in the operation of various machine tools,

l the invention is adapted to be applied with special advantages i g gfthe D P in the operation of grinding machines for shaping or renewing gggi g zgzg i i i izs g the shape of rolls such as those employed in metal rolling I a a i I a I s I 1 I Summary i 2 10 In the operation of large installations for the rolling of steel Brief Description of the Drawings 3 or aluminum into thin Sheets or Strips for comng, the high Descnpnon of Preferred ,Embodlments 4 inter-roll pressures and roll speeds result in severe wear of the An Exqmplally -P? -l'v 'q" 4 surfaces of the individual rolls. The wear is often non-uniform, (39mm! lnstrumemahnes on the Grmdmg and any roll surface irregularities result in magnified surface gi 'g g 2 5 imperfections in the sheets or strips. It is common practice to 7 change the rolls in a given mill stand frequently, as often as S yres .ervomotor once per eight hour shift. When each worn roll is removed iggg igggfi fifs g i from the mill, there is a need to have its surface re-finished or prox'imity re-ground to nearly perfect smoothness and with the desired C L Control system cylindrical shape (which may be a convex or concave contour Contouringpp 10 lengthwise of the roll to compensate for roll loading pressure Sequence Command 13 and produce a desired cross sectional shape in the rolled D, M I A y 14 strip). To keep a large mill, and the investment which it D gg zggigggi g l 5 represents, operating efficiently, it is desirable to re-grind l 1. Setup Procedure 16 wom mus not only quickly so that they may be returned to service, but also with precision. Location of Lengthwise Camel-7M6] 18 The increasiii 1 severe shorta e of skilled machinists leads (a) Movement of the Swivel Base to the Center g y g to the result that manual control of grinding machines offers OfB.AXIS Travel little p p f fy g the current demand for pi and (b) sctfmg the Platform 35 to the Center of X precise grinding of rolls. The present invention aims to over- AXIS Travel come that if y y making g g operaions (C) W W?" of Proxlmny Swltches to Opera stantially fully automatic through the use of pre-calculated, tlve Positions Pr g a m a a of t ki d i p fi e at efine (d) Movementflfwhedto Cememf B 20 the contour of the finished roll surface, and sequence com- Auwmanc Ahgmflem of the AXIS 24 Y mands which call for the execution of different routines in suc- (a) Startup Operations 24 cession, and with preselected operating parameters The need (b) Movement to Locatlon of Flrst Gagmg Band 26 for a machinist of extreme skill is thus obviated and the speed (c) Bringing the Wheel into Touching Contact w h th R0 28 with which any roll can be completely reground is increased (d) Grinding Right Gage Band to predetermined beyond that attainable by even the most skilled operator.

Depth 28 SUMMARY OF THE INVENTION (e) Movement of Wheel to Location of Left Gage Band 29 A pmlcpal P l F" Pmvde ,melhods (f) Grinding of the Left Gaging Band 30 and apparatus tor the machining of workpieces to desired con- (g) Retraction of the Wheel Free of the Roll 30 P and by smcessmn "f' 0 Sensing the Location of the Left G aging Band ried out automatically in sequence, and all defined in advance on the Rear Side of the R011 31 by Programmed l is 9 Determining Direction of First Gn-nding Pass program of success ve instructions defining successive multimH-G rindiiig: .I:T..TI. .TTT. 37 am movements which make? up a i (a) Right End Larger H U u and which may be followed in the machining of a plurality of (b) Left End Larger .I.....II.II 39 "F W have Same l P and (c) m of the System Prior to First Grinding con unction with such a profile program, to utilize a program Pass 4o l P i ((0 First Grinding Pass and Continuous Passing" piece or a group of identical workpieces so as to br ng about (i) Case I -Material Removal Incomplete 42 3 i; z i of 2 5 22 opegnons mcluimg a mgou n using orap r o eproieprogramw en 5 g gf gg Rem9lcomplete" that is required in the machining of the workpiece. Finish Grinding 45 It is another object of the invention to facilitate the use of Sensing and 46 the same program of profile data in the shaping of surfaces of 8. Cleaning p the R0 Surface y a plurality cylindrical workpieces such that the surface con- Passes' 50 tours are symmetrical about the lengthwise centers of the 9. polishinpgsggs. 52 workpteces, even though the Exact length of any particular -g a Second one of the workpieces is not known or measured and the axial An Alternative Embodiment placement of the workpiece in a numerically controlled grinding machine is not determined by a painstaking and time-consuming setup procedure.

in a more specific sense, it is an object of the invention to eliminate the need for a long and detailed numerical program to be prepared (and represented on an individual punched tape, according to current practice) for each individual specific workpiece in a series of workpieces which are to have the same final profile but which are to be made with different CROSS-REFERENCE To A RELATED APPLICATION final sizes (e.g., lengths or diameters), and a related object is This application is a division of my copending application, to provide methods and apparatus by which (a) a single profile Ser. No. 790,323, filed Jan. 10, 1969. program of numerical instructions is used with any one of a 

1. The method of controlling a machine tool to shape a workpiece according to a numerically defined path, while performing sequentially a plurality of different operations ancillary to the shaping, comprising the steps of storing in digital form a series of instructions defining successive increments of relative multiaxis movement between a tool and a workpiece which make up a desired profile path, storing in digital form sequential commands designating different ones of a plurality of ancillary routines, a first type of said routines being independent of the profile path and a second type of said routines requiring motions following in whole or in part the profile path, reading the commands in sequence from storage and causing them to produce in sequential order the ancillary routines designated thereby, and in response to the reading of a command of said second type reading said instructions from storage and causing each to produce in succession the multi-axis incremental movement which it defines until the total movement designated by the commanded second type of routine has been executed, said stored instructions being repeatedly used as often as called for by said commands.
 2. The method set forth in claim 1 wherein any command may include an indication of desired feed rate, and multi-axis movement according to the instructions carried out at the feed rate most recently read from storage as a part of a command.
 3. The method set forth in claim 1 including the step of signaling the completion of each command after it has been read from storage, and in response to such signaling reading the next command from storage.
 4. The method set forth in claim 1 wherein at least some of said commands include a designation of the thickness of material to be removed from the workpiece in the direction of one axis, at least some of the second type of commands call for repeated execution of the contoured path motion with relative incremental infeed of the tool toward the workpiece along said one axis after each such execution, and in the carrying out of the latter category of command characterized by the steps of determining the thickness of material removed after each execution of the path motion, and terminating the repeated execution of the path motions when the measured removal equals the designated removal.
 5. The method of controlling a machine tool to shape a workpiece according to a numerically defined path while performing sequentially a plurality of special operations ancillary to the shaping; comprising the steps of storing in digital form a series of instructions defining successive increments of relative multi-axis movement between a tool and a workpiece which make up a desired contoured path; storing in digital form sequential commands designating the sequential steps to be carried out in the shaping of the workpiece; a first type of said commands defining auxiliary functions and a second type of said commands designating relative motion between the tool and the workpiece; reading said commands in sequence from storage and executing each command before reading the next; and in response to the reading of each command of the second type, reading sequentially said instructions from storage and executing each instructed multi-axis increment of movement before reading the next instruction, and terminating the reading of instructions from storage when the total movement equals the motion designated by the previously read command.
 6. The method of controlling a machine tool to shape a workpiece according to a numerically defined path while performing sequentially a plurality of ancillary operations, comprising the steps of preparing a first eLongated digital record having successive blocks of numerical instructions defining the successive increments of multi-axis relative movement between a tool and a workpiece which make up a desired profile, preparing a second elongated digital record having successive blocks of numerical or code commands designating the successive ancillary operations which are to be performed in sequence, a first type of said commands designating auxiliary functions to be executed and a second type of said commands designating the extent of relative motion to be effected between the tool and the workpiece, passing the blocks of said second record one at a time in sequence through a second record reader to produce a set of command signals corresponding to each block, utilizing each set of command signals corresponding to a command of the first type to carry out the auxiliary function designated thereby; and utilizing each set of command signals corresponding to a command of the second type to initiate the passing of the blocks of said first record one at a time through a first record reader to produce a set of instruction signals corresponding to each block, utilizing each set of instruction signals to cause the tool and workpiece to execute the multi-axis increment motions defined thereby, and terminating the operation of said first reader when the total executed relative motion equals the extent designated by the command of the second type.
 7. The method set forth in claim 6 characterized in that said second reader is stopped after the reading of each block of the second record, a completion signal is generated after execution of the command designated by a set of command signals, the second reader is restarted in response to a completion signal; the first reader is stopped after the reading of each block of the first record, a complete signal is generated after execution of the multi-axis increment motion defined by a set of instruction signals; the first reader is restarted in response to a complete signal; and in response to a complete signal when the total executed relative motion equals the extent designated by a command of the second type, the first reader is not restarted but a completion signal is generated to restart the second reader.
 8. The method set forth in claim 6 further characterized in that said first record is an endless tape which is repetitively read by successive passings through the first reader, whereby total multi-axis movement in whole or in part following the desired profile may be produced.
 9. The method set forth in claim 8 and further characterized in that the desired profile is symmetrical about a reference point on one axis.
 10. In a system for controlling a machine tool to cause a tool movable along multiple axes relative to a workpiece to shape the latter with a contoured path while performing sequentially different operations ancillary to the shaping, the combination comprising first means for storing in digital form a series of instructions defining successive increments of relative multi-axis motion which make up the contoured path, second means for storing in digital form sequential commands designating different ones of a plurality of ancillary routines, a first type of said routines being independent of the contoured path and a second type of said routines requiring relative motions between the tool and workpiece following the contoured path in whole or in part, means for reading said command in sequence from said second storing means and in response to each producing the ancillary routine designated thereby, means responsive to reading of a command of the second type from said second storing means for initiating the reading of successive instructions from said first storing means, means responsive to the instructions read for moving the tool relative to the workpiece along the successive increments of said contoured path until the total movement designated by the command of the second type has been executed, and means responsive to the terminaTion of the reading of instructions from said first storing means for initiating the reading of the next command from said second storing means.
 11. In a system for controlling a machine tool to cause a tool movable along multiple axes relative to a workpiece to shape the latter with a contoured profile while performing different operations ancillary to the shaping, the combination comprising a first record reader adapted to receive a first elongated digital record having successive blocks of numerical instructions defining the successive increments of multi-axis relative movement between the tool and the workpiece to make up the contoured profile, a second record reader adapted to receive a second elongated digital record having successive blocks of numerical or code commands designating the successive ancillary operations which are to be performed in sequence, a first type of said commands designating auxiliary functions to be executed and a second type of said commands designating the extent of relative motion to be effected between the tool and the workpiece, means for operating said second reader to read one block from said second record at a time, means for executing the command read from a block and restarting the second reader to the next block of the second record, means responsive to the reading of a command of the second type for starting said first reader to read the instructions from successive blocks on the first record, means responsive to the reading of each instruction for causing the incremental relative multi-axis movement represented thereby and then restarting the first reader to read the next block of the first record, and means for terminating the restarting of the first record when the total executed relative motion equals that designated by the previously read command of the second type and restarting said second reader. 